
Closed
Posted
Paid on delivery
The immediate goal is to deliver a highly secure escrow app for both iOS and Android that handles P2P, B2B, P2B and B2P transactions right out of the gate. Bank-grade encryption, a strict zero-trust architecture, and full OWASP compliance are non-negotiable pillars of the build. Phase 1 – Mobile First • Design and code the core escrow workflow for peer-to-peer and business-to-business payments. • Implement strong customer authentication, role-based access, and end-to-end encrypted data at rest and in transit. • Integrate a modular backend API so we can later expose the same services to a web portal and USSD interface without rewriting business logic. Security & Compliance Every line must pass automated OWASP checks, static code analysis, and peer review. Key vault management, token-based sessions, and granular audit trails are required so the platform is ready for future PCI DSS and SOC 2 audits. Payments & Wallets The app should be architected to plug into popular mobile wallets and local payment rails (think Apple Pay, Google Pay, and regional wallets) through clear adapter classes. A sandbox integration that demonstrates at least one live mobile wallet transaction will form part of acceptance testing. Tech Stack Native Swift/Kotlin or a robust cross-platform framework like Flutter or React Native is acceptable; I’m open to your professional recommendation as long as performance, security, and code maintainability are fully addressed. A containerised backend (Node.js, Java Spring, or similar) running behind an API gateway with JWT or OAuth 2.0 is preferred. Deliverables (MVP) 1. Universal iOS and Android apps compiled for App Store and Google Play internal testing. 2. Secure backend API with full documentation and Postman collection. 3. Admin/ops panel (basic) for dispute management and escrow release. 4. Automated test suite covering critical paths and security checks. 5. Deployment scripts (CI/CD) and hand-over documentation. Acceptance Criteria • All P2P and B2B flows complete without data leakage, meeting OWASP Top 10 standards. • End-to-end transaction completes in <4 seconds on 4G. • Codebase passes independent penetration test with zero critical findings. • Source, docs, and build pipelines delivered in my private repo. Web and USSD channels come next, so clean architecture and modular code are essential. Let’s build a rock-solid foundation that scales safely into those future phases.
Project ID: 40385716
273 proposals
Remote project
Active 21 days ago
Set your budget and timeframe
Get paid for your work
Outline your proposal
It's free to sign up and bid on jobs
273 freelancers are bidding on average $708 USD for this job

Greetings from Logictrix! My name is Jas, and I am looking forward to discuss about your app in details over the Chat or Call. We have enough app developers available in team so I can assure you to deliver this project at a fairly low cost with great quality and with a commitment for long term support. *** We have earned 'Expertise' level in AI development and used many AI platforms like openAI, Freepik, Antigravity, Cursor etc for App development and other AI work! *** We have developed around 400+ Android and iOS apps using Native and Flutter SDK in the past 15 years, Many apps are Live in Google play and App store. We will share our detailed portfolio over the Chat once we connect. Looking forward to your reply... Thanks and Regards Jas
$500 USD in 10 days
9.7
9.7

With your project requiring a trustworthy escrow app, my team at CnELIndia is perfectly suited for the task. Boasting of 18 years in the industry, we are experts at building secure, cross-platform mobile applications using robust tech stacks like Native Swift/Kotlin or top-flight cross-platform frameworks like Flutter & React Native. Your project emphases performance & security, which is right up our alley as we pride ourselves on implementing bank-grade encryption, and strict zero-trust architecture. Additionally, our in-depth experience with API Development will ensure seamless integration with popular mobile wallets and local payment rails. These integrations will be solidly built through clear adapter classes that can be expanded to expose similar services in web and USSD interfaces without disrupting the core logic. We understand the pressing need for strict adherence to OWASP compliance and have the expertise to deliver this critical aspect of your app. Your project doesn’t end with its initial release; it needs to scale securely into future phases. At CnELIndia, we have a meticulous approach to projects which includes granular audit trails, thorough independent testing, and delivering exhaustive documentation to ease future audits. Let us leverage our skills and unmatched commitment to hard work to build this rock-solid foundation for you.
$500 USD in 7 days
9.0
9.0

Hello, With deep expertise in mobile app development and PHP, our team at Our Software is thrilled at the prospect of building your highly secure escrow app. We understand and prioritize your non-negotiable pillars of bank-grade encryption, zero-trust architecture, and full OWASP compliance. Having designed and developed numerous mobile applications that integrate with leading payment systems, like Apple Pay and Google Pay, we believe we have the skillset for the job. Your request for a mobile-first design aligns perfectly with our core competencies. We specialize in designing user-friendly workflows, implementing granular security measures, and integrating modular backends for flexible scalability. We are also experienced in conducting stringent penetration tests to ensure robust security. As an added bonus, we offer clean architecture and modular code which will be essential for future phases such as web and USSD channels. At Our Software, we always aim to exceed expectations by delivering on time, providing detailed documentation ensuring easy handover and above all ensuring excellent post-production support. Choose us for a secure yet scalable escrow platform that will revolutionize P2P, B2B, P2B and B2P transactions. Thanks!
$450 USD in 3 days
8.6
8.6

Hello!! "Mobile Escrow Platform Development I have similar kind of expertise and work experience. I have gone through your requirements and understand that you are looking for highly skilled, qualified, and experienced (Android & iPhone /ipad) Mobile App with development API web services where admin can manage the app from backend development I would approach your project by starting with wireframes and getting the UI/UX design completed, before starting the actual development phase. We'll provide You high Quality Design and development for you with unlimited changes in design. ++++++Service Guarantee++++++ ➥ Designed app Android iOS admin panel. ➥ Optimized code and well commented on use for future. ➥ All the latest code to support all versions of Android and iOS phone devices. ➥ Launched the app on Google Play Store as well as Apple App Store. ➥ Setup servers, hosting your app and create a database. ➥ Free support and maintenance. ➥ Multi language support. ➥ 24*7 hours live support. ➥ daily weekly meeting Come with us through Chat Window and I'll show You over there what work we have done on previous projects. We'll provide You high Quality Design and development for you with unlimited changes in design. anticipating your response Concerning Christina
$494 USD in 9 days
8.4
8.4

Good to see this project, I will deliver the escrow MVP — cross-platform mobile apps (Flutter), containerized backend with JWT/OAuth 2.0 behind an API gateway, admin panel for disputes and escrow release, and a full CI/CD pipeline. For the modular backend, I will structure each payment adapter behind a clean interface layer so adding USSD, web, or new wallet rails later means writing one adapter class — no rewrites to your core escrow logic. Vault-managed secrets and granular audit logging will be baked in from day one to smooth your path toward PCI DSS and SOC 2 readiness. Questions: 1) Do you have a preferred payment processor or mobile wallet for the sandbox demo — or should I architect around a specific regional rail? 2) Will the admin panel need role-based access for multiple ops team members, or is a single admin role sufficient for MVP? Ready to start whenever you are. Kamran
$270 USD in 10 days
8.5
8.5

Mobile app developer Hello I have reviewed your project requirements, I can help you develop a rock-solid and highly secure mobile escrow platform as per your needs. I have in-depth experience in API development, Native Swift/Kotlin, and cross-platform frameworks like React Native and Flutter – which means we can bring your project to life with whatever tech-stack you choose. I’ve successfully launched multiple production apps across Google Play and App Store, delivering secure, optimized, and user-friendly solutions. ⭐Due to NDAs, links aren’t public—but once you open the chat, I’ll share live demos and walkthroughs. I’d be happy to discuss your requirements and execution plan. Bid amount is a placeholder and can be discussed over chat. Thanks & Regards Ranjana
$500 USD in 7 days
8.2
8.2

⭐⭐⭐⭐⭐ Build a Secure Escrow App for iOS and Android Transactions ❇️ Hi My Friend, I hope you're doing well. I've reviewed your project needs and see you're looking for a secure escrow app for both iOS and Android. You don't need to look any further; Zohaib is here to help you! My team has completed over 50 similar projects for secure payment solutions. I will design the core escrow workflow, implement strong security measures, and ensure full compliance with OWASP standards. ➡️ Why Me? I can easily create your escrow app as I have 5 years of experience in mobile app development and secure payment systems. My expertise includes Swift, Kotlin, API integration, and data encryption. Additionally, I have a strong grip on backend technologies like Node.js and Java Spring, ensuring a reliable and secure application. ➡️ Let's have a quick chat to discuss your project in detail, and I can show you samples of my previous work. I'm excited to explore this opportunity with you! ➡️ Skills & Experience: ✅ Mobile App Development ✅ Swift & Kotlin ✅ Secure Payments ✅ API Integration ✅ Data Encryption ✅ OWASP Compliance ✅ User Authentication ✅ Modular Architecture ✅ Automated Testing ✅ CI/CD Deployment ✅ Backend Development ✅ Peer-to-Peer Transactions Looking forward to your response! Best Regards, Zohaib
$350 USD in 2 days
7.8
7.8

Hi, You need a zero-compromise escrow app where security, speed, and clean architecture are built in from day one not patched later. I will build: • Build a secure escrow workflow (P2P/B2B) with strong auth, RBAC, encrypted transactions, and audit trails • Create a modular backend (API-first) with wallet adapters for Apple Pay/Google Pay and future web/USSD expansion • Implement CI/CD, automated security scans, and a tested <4s transaction pipeline with sandbox wallet integration You’ll get a bank-grade foundation ready for audits, scaling, and multi-channel expansion without rework and I’ve built secure fintech systems with encrypted flows, payment integrations, and audit-ready architectures Do you already have a preferred payment processor or should I recommend one based on your target regions? I can start immediately and map this into a sprint-based build with security checkpoints from day one. I am waiting for your response. Thanks.
$500 USD in 7 days
7.9
7.9

Hi, the clean way to build this is around a strict escrow state machine, not just payment screens. A real flow would be: user creates a transaction -> system verifies identity and role -> payer funds the escrow through the wallet adapter -> funds move into a protected held state -> counterparty fulfills the condition -> admin or rules engine resolves release or dispute -> every transition is logged, signed, and exposed through the same backend API for future web and USSD channels. That is what keeps the platform secure and extensible instead of just functional on mobile. These systems often look solid, but fail when payment callbacks, escrow status, and permission checks are handled separately. One real issue is a wallet callback confirming payment while the escrow record or audit trail is only partially updated, so I would handle it with atomic transaction handling, idempotent payment events, and a locked state model behind every release action. The part to get right early is the escrow lifecycle and security boundary between mobile, API, and payment adapters, because that drives both usability and correctness.
$500 USD in 7 days
7.2
7.2

Hi, I can develop your secure escrow MVP for iOS and Android with support for P2P, B2B, P2B, and B2P transactions. The system will be built with strong security (OWASP standards), encrypted data handling, role-based access, and a clean API-first backend so it can easily expand to web and USSD later. It will include wallet integration (Apple Pay / Google Pay ready), an admin panel for dispute handling, CI/CD setup, and full documentation. Everything will be built for speed, security, and scalability from day one, with a clean handover at the end. Thanks
$500 USD in 7 days
7.5
7.5

Hi, At Doomshell, we specialize in building secure, fintech-grade applications with a strong focus on scalability, compliance, and clean architecture—perfect for your escrow platform vision. Our approach: We’ll design a mobile-first, security-first architecture where every layer—from app to backend—is built around zero-trust principles, encryption, and modular scalability for future web and USSD expansion. Phase 1 – Mobile App (iOS & Android): • Cross-platform build (Flutter / React Native with native modules where needed) • Complete escrow workflows for P2P & B2B transactions • Strong authentication (MFA, biometric, token-based sessions) • Role-based access control (user, business, admin) Backend & Architecture: • Containerized backend (Node.js / Spring Boot) behind API Gateway • REST APIs designed for reuse (web + USSD ready) • JWT/OAuth 2.0 authentication • Modular service layer for payments, escrow logic, and users Security & Compliance: • End-to-end encryption (in transit + at rest) • OWASP Top 10 compliance (automated + manual checks) Why Doomshell: ✔ Experience with secure fintech & payment systems ✔ Strong focus on OWASP, scalability, and clean architecture ✔ Future-ready design for web & USSD expansion Quick questions: • Which region/country will this launch in (for payment compliance)? • Any preferred cloud provider (AWS, GCP, Azure)? We’re ready to build a secure, scalable escrow platform that meets enterprise-grade standards from day one. Best regards,
$720 USD in 5 days
7.5
7.5

Hi, Building a multi channel escrow engine requires a "security by design" architecture where the business logic is entirely decoupled from the presentation layer. At Plan D Studios, we bring 12+ years of experience in Security and Mobile App Development, specializing in financial grade systems that utilize zero trust protocols and OWASP compliant coding standards. Our Engineering Strategy for Phase 1: Modular Core: I’ll architect the backend in Node.js using a hexagonal pattern, ensuring the API Development is ready for your future Web and USSD channels without logic duplication. Encrypted Mobile Build: Using Flutter, I’ll deliver high performance iPhone and Android apps featuring certificate pinning, root/jailbreak detection, and AES 256 encryption at rest. Payment Adapters: Implementation of clean adapter classes for seamless integration with Apple Pay, Google Pay, and local mobile wallets via OAuth 2.0 and JWT. Audit Readiness: Every transaction will generate an immutable audit trail, architected for future PCI DSS and SOC 2 compliance. We handle all development in house to maintain strict "zero leakage" data integrity. Regarding the dispute management: Do you want the escrow release to be strictly automated based on external shipping/delivery triggers, or should the admin panel support a multi sig manual override for high value B2B transactions? Regards, Haider
$500 USD in 7 days
7.4
7.4

Hi there, I’ve reviewed your Flutter app requirements and would love to help. With 5+ years of experience in cross-platform development, I specialise in clean UI, smooth performance, and robust API integration. I’ll begin with clear planning, share regular progress updates, and ensure the app is fully tested before launch. Let’s connect to discuss your vision — I’m ready to get started! Best, Bhargav Flutter Developer | Android & iOS Expert
$500 USD in 7 days
7.1
7.1

Hi I have strong experience building secure transaction platforms with mobile apps, backend APIs, role-based access control, audit logging, and payment integrations where security and clean architecture are the highest priorities. The main technical challenge in this escrow MVP is not only completing P2P and B2B flows, but designing them under a zero-trust model so authentication, wallet integration, dispute handling, and future expansion to web and USSD all remain secure and modular. I would approach this with Flutter for a shared mobile codebase, backed by a containerized API layer with strict RBAC, JWT or OAuth 2.0, encrypted secrets management, adapter-based payment integrations, and full audit trails for every escrow action. Security would be built into the workflow from the start through OWASP-aware API design, static analysis, secure storage, encrypted transport, code review discipline, and automated testing across critical paths. I’m also comfortable structuring the backend so the same business logic can later power the web portal and USSD layer without rework. The result would be a maintainable foundation with secure mobile apps, a basic ops panel for disputes and release actions, documented APIs, CI/CD pipelines, and a codebase ready for future PCI DSS and SOC 2 preparation. This is the kind of project where disciplined architecture matters as much as feature delivery, and that is exactly how I work. Thanks, Hercules
$500 USD in 7 days
6.9
6.9

Hi Dear, We can build this using a secure and scalable tech stack such as Flutter or native (Swift/Kotlin) for mobile apps, combined with a containerized backend (Node.js/NestJS or Java Spring Boot) behind an API gateway. The solution will include OAuth/JWT-based authentication, end-to-end encryption, OWASP-compliant coding practices, audit logs, modular payment integrations (Apple Pay, Google Pay), and CI/CD pipelines with automated security testing—ensuring readiness for future compliance like PCI DSS and SOC 2. A few questions to better understand your requirements: ============================================== Do you have a preferred cloud infrastructure (AWS, GCP, Azure) for hosting and key management? Which regions will the app initially launch in (to align with payment and compliance requirements)? Should biometric authentication (Face ID/Fingerprint) be included in the MVP? Do you want dispute resolution to be fully manual or partially automated in the first phase? Best Regards, Srashtasoft Team
$500 USD in 7 days
7.2
7.2

Hello, I can build a secure, scalable escrow app for iOS and Android that supports P2P, B2B, and other transaction types with bank-grade encryption and zero-trust architecture. I have experience implementing OWASP-compliant workflows, strong authentication, and encrypted data handling. Using native Swift/Kotlin or Flutter/React Native, I will ensure performance and security while maintaining clean, modular code ready for future expansion, including web and USSD. I also bring expertise in developing secure backend APIs with token-based sessions, audit trails, and integration of mobile wallets like Apple Pay and Google Pay with sandbox testing. I will provide comprehensive documentation, automated test suites, and deployment scripts to ensure smooth internal testing and handover. Thanks, Teo
$300 USD in 3 days
6.6
6.6

Hello! As per your project post, you’re looking to build an Mobile Escrow Platform for iOS and Android that supports P2P, B2B, P2B, and B2P transactions with a strong focus on security, compliance, and scalability. The system must follow zero trust principles, support modular backend architecture, and be ready for future expansion to web and USSD interfaces. The goal is to deliver a production ready MVP that ensures secure transactions, auditability, and seamless wallet integrations. My focus will be on delivering a complete escrow platform, featuring: secure escrow workflows with role based access control, end to end encryption for data in transit and at rest, modular backend APIs with token based authentication, wallet integration layer supporting Apple Pay Google Pay and regional providers, and an admin panel for dispute handling escrow release and audit tracking with detailed logs. I specialize in secure full stack development with strong experience in fintech systems, API architecture, and compliance driven platforms. My focus is on building scalable, secure applications aligned with OWASP standards, ensuring performance, reliability, and audit readiness from day one. Let’s connect to review your compliance requirements, transaction flows, and define a clear MVP architecture and execution roadmap. Best regards, Nikita Gupta.
$300 USD in 22 days
6.8
6.8

Hi, We would like to grab this opportunity and will work till you get 100% satisfied with our work. We are an expert team which have many years of experience on PHP, Mobile App Development, iPhone, Android, Node.js, iOS Development, React Native, Flutter, Security, API Development Please come over chat and discuss your requirement in a detailed way. Regards
$500 USD in 7 days
6.3
6.3

Your escrow platform will fail penetration testing if the JWT implementation doesn't include refresh token rotation and proper key management. I've seen three fintech apps get rejected by auditors because they stored signing keys in environment variables instead of using AWS Secrets Manager or HashiCorp Vault. Before architecting the solution, I need clarity on two things. First - what's your target transaction volume at launch? If you're expecting more than 1,000 concurrent escrow holds, we'll need distributed locking with Redis to prevent race conditions during fund releases. Second - which regional payment rails are you prioritizing? Integration patterns for M-Pesa versus Stripe versus local ACH networks are completely different, and that drives the adapter architecture. Here's the architectural approach: - FLUTTER + NATIVE MODULES: Build the UI in Flutter for 80% code reuse, then write Swift/Kotlin security modules for biometric auth and keychain storage because Flutter's crypto libraries don't meet bank-grade standards. - NODE.JS + POSTGRESQL: Implement event sourcing for the escrow state machine so every transaction step is immutable and auditable. This gives you the audit trail for SOC 2 without bolting it on later. - OWASP COMPLIANCE: Run Snyk and SonarQube in the CI pipeline with zero-tolerance policies. I'll configure pre-commit hooks that block any code with SQL injection vectors or hardcoded secrets. - API GATEWAY + OAUTH 2.0: Deploy Kong or AWS API Gateway with rate limiting per client and IP. JWT access tokens expire in 15 minutes with HttpOnly refresh tokens to prevent XSS attacks. - ZERO-TRUST ARCHITECTURE: Encrypt all database fields containing PII using AES-256 with per-record keys stored in AWS KMS. Even if someone dumps the database, they get ciphertext. I've built two escrow platforms that passed PCI DSS Level 1 audits and handled $40M in transaction volume. One processed 15K transactions daily with sub-2-second response times using the exact stack I'm proposing here. Let's schedule a 20-minute technical call to walk through the state machine design and discuss your penetration testing requirements before we finalize the architecture.
$450 USD in 10 days
7.3
7.3

Hi, You’re aiming for a bank-grade escrow platform—so the focus must be on architecture and security from day one, not just feature delivery. I can help you build a secure, scalable MVP that’s ready for audits and future expansion (web + USSD) without rework. I recommend Flutter for fast, consistent mobile delivery, paired with a Node.js (NestJS) or Java Spring Boot backend using a modular, domain-driven design. The backend will sit behind an API gateway with OAuth 2.0 / JWT, strict RBAC, and a zero-trust approach (service-to-service auth, minimal privileges). Security will include end-to-end encryption, secure key management (Vault/KMS), OWASP Top 10 compliance, audit logs, and automated SAST/DAST pipelines. Payment architecture will use adapter patterns for wallets (Apple Pay, Google Pay, regional rails), ensuring easy expansion. Deliverables will include tested mobile apps, secure APIs, admin panel, CI/CD pipelines, and full documentation. Timeline: ~4–6 weeks for MVP Rate: Based on scope—can break into milestones. With Regards! Apurva
$500 USD in 7 days
6.6
6.6

Banjul, Gambia
Payment method verified
Member since Apr 20, 2019
$10-30 USD
$30-250 USD
$25 USD
$30 USD
$250-750 USD
₹1500-12500 INR
$250-750 USD
£20-250 GBP
$30-250 USD
$3000-5000 USD
€30-250 EUR
₹12500-37500 INR
$250-750 USD
$250-750 USD
₹1500-12500 INR
₹750-1250 INR / hour
$250-750 USD
₹12500-37500 INR
$250-750 USD
$1500-3000 USD
₹75000-150000 INR
$10-30 USD
£20-250 GBP
$250-750 USD
€250-750 EUR