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Our eKYC platform is live, but the two-factor authentication built into the public weblink is failing consistently. Users receive the OTP/SMS push, enter the code, and the process stalls with a generic “authentication error” before redirecting them back to the login page. Server logs show no obvious stack trace, so I need someone to dig in, reproduce the fault, and patch it without disrupting the rest of the flow. What I know so far • Front-end: React single-page component that posts to a Node/Express API • Auth layer: JWT for the first factor, OTP via Twilio for the second • Database: PostgreSQL 14 • Error appears only in production, not in our staging environment Your job 1. Trace the call from the React form through the Express middleware to pinpoint why the OTP verification step breaks. 2. Repair or refactor the relevant code (JavaScript/TypeScript) so a valid OTP completes the login and issues the final JWT. 3. Suggest any security hardening or rate-limiting tweaks you notice while inside the code. 4. Provide a short summary of the fix and the files touched so my team can review and deploy. You will receive Git access to a dedicated branch and, if needed, limited read-only production logs. I’m ready to test a working patch right away, so please indicate how soon you can start and roughly how long you expect the investigation to take.
Project ID: 40688040
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69 freelancers are bidding on average ₹7,527 INR for this job

Your eKYC 2FA is stuck in a loop and users can't complete login. I've built and debugged many React/Node/Twilio auth flows like this. Here's what I'll do for you: • Pinpoint the exact spot in your React/Express/Twilio flow where the OTP verification is failing. • Fix the code so valid OTPs get users logged in and issue the final JWT. • Suggest any quick security or rate-limiting improvements I spot. • Provide a clear summary of the changes and files touched. I can start right away and expect to have a working patch for you within few hours. You only release payment once you've tested the fix and are 100% happy. Message me so we can get this sorted.
₹7,000 INR in 1 day
8.6
8.6

Prod-only failure that clears in staging almost always means something that only exists under a real deploy topology: a load balancer, a separate session store, a proxy stripping or rewriting headers. Twilio OTP verify with a generic auth error and no stack trace fits that pattern well, since a reverse proxy in front of Express can silently drop or rewrite the session cookie, or requests can land on a different app instance than the one that generated the OTP if sessions aren't in a shared store like Redis or Postgres. JWT clock skew across containers is another common one, and if Twilio webhook signature validation is in the path at all, a load balancer terminating TLS and rewriting the request can break that check too while staging behind a single box never sees it. I'd start by tracing the exact OTP verify request through each hop in prod, comparing headers, cookies and session state against what staging produces for the same flow, rather than guessing at the fix first. Given it's React to Express to Postgres, I'd check whether sessions are sticky to one instance or shared, whether the OTP record and its expiry are read from the same source the verify step checks, and whether the proxy config differs from staging in anything touching headers or cookies. Once the root cause is confirmed I'd patch it without touching the rest of the auth flow, then look at rate limiting on the OTP endpoint and basic hardening around retry attempts and expiry. 37500 INR over 4 days is where I'd start, but I haven't seen your proxy or session config yet and that's what would move the number once I'm actually in the logs. M1: trace the OTP verify path end to end in prod, isolate root cause, $15000, 2 days. M2: patch the fix, verify the rest of the flow still passes, add OTP rate limiting and hardening, $22500, 2 days. Send me access to the prod logs and the proxy/session config and I'll start on M1 straight away.
₹37,500 INR in 4 days
6.4
6.4

Hi there, I understand you're experiencing issues with your eKYC platform's 2FA authentication, specifically with the OTP verification step. I'd be happy to help resolve this issue. - Investigate the call from the React form to the Express middleware - Repair or refactor the relevant JavaScript/TypeScript code - Suggest security hardening and rate-limiting tweaks - Provide a summary of the fix for your team's review Skills: ✅ React and Node/Express development ✅ JWT and Twilio integration ✅ PostgreSQL database management ✅ JavaScript/TypeScript debugging I'm ready to start ASAP. Looking forward to resolving this issue for you. Best regards!
₹2,000 INR in 1 day
5.7
5.7

Hi there, I see your eKYC 2FA is live but the OTP verification keeps throwing "authentication error" in production only — that's a tricky one since staging passes fine. The culprit is likely a timing issue with token validation, a mismatch in JWT secret loading between environments, or an OTP expiry race condition. I'll trace the React form → Express middleware → PostgreSQL lookup, reproduce the fault, and patch it without touching the rest of the flow. What I'll do: ✅ Reproduce the OTP failure with production logs and local debugging ✅ Fix the verification logic so valid OTPs complete login and issue the final JWT ✅ Add rate-limiting and security hardening suggestions (OTP retry limits, brute-force protection) ✅ Deliver a clear summary of changes and files touched for your team's review Skills: ✅ 7+ years debugging Node.js/Express API issues and JWT auth flows ✅ PostgreSQL 14 — query optimization, transaction debugging, token storage ✅ Twilio OTP integration and SMS deliverability issues ✅ React SPA authentication troubleshooting (CORS, token handling, race conditions) ✅ Security hardening: rate-limiting, brute-force protection, JWT best practices ✅ Microsoft® Certified: MCSA | MCSE | MCT ✅ 300+ projects delivered, 280+ five-star reviews Why me: Fast responses, senior-level debugging, and I'll work until your OTP flow is fully fixed.
₹7,000 INR in 2 days
5.8
5.8

Hi, The fact that OTP works in staging but fails only in production suggests this could be related to environment configuration, JWT handling, Twilio settings, middleware flow, or production-specific API behavior. I have experience with API integrations and messaging-related platforms, including MsgHub, along with backend debugging and REST API development. I can trace the complete OTP flow, identify where the verification is breaking, and provide a clean patch with details of the files changed. Can you share whether production and staging use the same Twilio configuration and environment variables? Also, can the issue be reproduced with a test account? I can start investigating as soon as access is available.
₹12,000 INR in 7 days
5.9
5.9

Hi, Production-only OTP failures with no stack trace usually point to environment-specific config drift — session/cookie handling, a timing issue in the OTP verification call, or a middleware difference between staging and prod (proxy headers, CORS, or JWT clock skew are common culprits). My plan: trace the React form → Express middleware → OTP verification path with added structured logging around the failure point, reproduce it against prod-like config, then patch without touching the surrounding flow. I'll also flag any rate-limiting or hardening gaps I notice while in there. I work regularly across this exact stack — React, Node/Express, JWT auth, Twilio OTP flows, and PostgreSQL — so I can move quickly once I have branch and log access. Question: does staging point to the same Twilio account/config as production, or could that be part of the gap? Ready to start right away. Best regards, Davinder
₹7,000 INR in 5 days
5.6
5.6

Hi, I’ve worked with React, Node/Express, JWT authentication, Twilio OTP and PostgreSQL, including debugging authentication and API issues. I can trace the OTP flow from the React form through the Express API and find why the production flow is failing even though staging is working. I’ll reproduce the issue first, check the frontend request, middleware and OTP verification response, then patch the relevant code without changing the working first-factor login flow. I’ll also review the authentication code for obvious rate-limiting or security issues and document exactly what was changed. A few quick questions before we start: Can you provide access to the dedicated Git branch and the production logs you mentioned? Is the production environment using the same Twilio configuration as staging? Does the error happen with every valid OTP or only for certain users/numbers? I can start immediately and expect the initial investigation to take around 2–4 hours, depending on what I find in the production flow. I’ll provide the working patch along with a short summary of the issue and files changed.
₹7,000 INR in 7 days
4.5
4.5

I’ve gone through the issue carefully, and the production-only failure points to a mismatch somewhere between the React OTP submission, Express verification flow, Twilio response handling and final JWT issuance. I can trace that complete path, reproduce the failure using the available logs and code, and isolate the exact point where the valid OTP is being rejected or the authenticated state is being lost. I’ll patch the relevant JavaScript/TypeScript without disturbing the existing first-factor flow, then verify that valid OTPs complete authentication and invalid/expired codes remain blocked. While debugging, I’ll also review the OTP/JWT handling for practical security improvements such as verification rate limits, replay protection and safe error handling where applicable. The final delivery will include the fix, a concise list of touched files and a deployment/testing summary for your team. I can start with the dedicated branch immediately. Share the repository and relevant production log access, and I’ll begin by tracing the OTP request/response chain.
₹7,000 INR in 5 days
5.0
5.0

As a seasoned professional with over 6 years of experience in web and mobile development, I can thoroughly evaluate your eKYC platform's issues and deliver precise solutions. My strong understanding of Java, Node.js, and PostgreSQL will be invaluable in untangling the issues across the front-end, back-end, and database aspects of your platform. In the past, I have tackled complex bugs and their fixes efficiently; this project will be no exception. Going into the third aspect of your project description, I see that you are concerned about security hardening. Data security has always been a top priority in my projects, and my skills can lend itself to enhance your application - whether it involves rate-limiting techniques or other pragmatic safety measures. Discussing your specific requirements and exploring potential vulnerabilities is something my team is experienced in handling.
₹1,500 INR in 3 days
3.6
3.6

I can start immediately. I have 10+ years of experience debugging and fixing production PHP/JavaScript applications, APIs, authentication flows, JWT, OTP integrations, and PostgreSQL/MySQL systems. I’ll trace the complete 2FA flow from the React form → Express middleware → Twilio OTP verification → PostgreSQL → final JWT issuance, reproduce the production-only failure, and identify the exact cause without disrupting the existing login flow. Checkpoints: ✅ Reproduce and isolate the authentication error ✅ Review React + Node/Express middleware and JWT handling ✅ Verify Twilio OTP/callback configuration and production environment differences ✅ Patch/refactor the affected JavaScript/TypeScript code ✅ Add appropriate OTP validation, expiry, retry/rate-limit and security hardening ✅ Test valid/invalid/expired OTP scenarios ✅ Provide files changed + concise fix/deployment summary I’m available now and can begin as soon as Git access is provided. I expect the initial investigation to take around 2–4 hours, depending on the production-specific cause.
₹2,500 INR in 1 day
3.5
3.5

Hello! I can trace the React/Express OTP flow, fix the production-only Twilio/JWT failure, add rate-limiting/security hardening, and document the patch clearly. We can discuss details here.
₹10,000 INR in 7 days
2.8
2.8

The OTP failure in production often hides a mismatch between the Twilio webhook URL and the environment config used by the Node server. I’ll reproduce the flow locally, add detailed logging around the Express middleware, and then adjust the verification logic to correctly handle the returned code. Can start right away and push a clean patch to the dedicated branch once the root cause is isolated. A common mistake is assuming the OTP service always returns a string, while production sometimes receives a number, causing the JWT step to abort. You’ll see the login complete, the final JWT issued, and no extra redirects, all while keeping the existing security flow intact.
₹7,000 INR in 3 days
2.9
2.9

Hi there, I can investigate and fix the production-only OTP authentication issue across your React, Node/Express, Twilio, JWT, and PostgreSQL flow. I’ll reproduce the issue, trace the OTP request through the middleware and verification logic, identify the root cause, and patch it without affecting the existing authentication flow. I’ll also review rate limiting, OTP expiry, validation, error handling, and other security hardening opportunities, then provide a clear summary of the fix and files changed for your team. I can start immediately and expect the initial investigation to take around 4 to 8 hours, depending on the production/staging differences. Do you already have the relevant branch and production error logs ready to share? Kindly send me a message to discuss the access and start the investigation. Thank you!
₹8,000 INR in 5 days
2.6
2.6

Hello, I understand you need to fix the production-only 2FA issue in your eKYC platform where valid Twilio OTP verification ends with an authentication error instead of completing the JWT login flow. The goal is to identify the root cause and deliver a safe, reviewable patch without disrupting the existing authentication process. Here’s what I can provide: Trace the React → Node/Express → Twilio → PostgreSQL flow and reproduce the production issue. Fix/refactor the JavaScript/TypeScript OTP verification and final JWT issuance. Review security gaps and improve OTP rate limiting, validation and error handling where required. I bring over 4+ years of experience in JavaScript, Node.js, PostgreSQL, API development and authentication workflows, with a strong focus on secure and reliable applications. I can work directly on your dedicated branch, review available production logs and provide a concise summary of the root cause, fix and changed files. Just to clarify a few things: Is the production issue reproducible with every valid OTP or only certain users? Are production and staging using the same Twilio configuration and environment variables? Please come to the chat box to discuss more about your project. Best regards Indresh Kushwaha
₹10,000 INR in 7 days
2.4
2.4

Hello, I have 5+ years of experience in JavaScript, Node.js, React, PostgreSQL, API development and production debugging, and I can investigate and resolve the production-only OTP authentication failure without disturbing the existing eKYC flow. I will trace the complete flow from the React OTP form through the Express middleware, Twilio response/verification, PostgreSQL state handling and JWT issuance. I’ll compare staging vs production configuration, inspect request/response handling, async errors, token/session state and environment variables to identify the exact reason for the redirect and generic authentication error. Once reproduced, I’ll patch the relevant JavaScript/TypeScript code, validate successful OTP → final JWT → authenticated redirect, and test invalid/expired/reused OTP scenarios. I’ll also review OTP rate limiting, retry limits, token expiry, verification attempts and error handling for security improvements. I can start immediately and provide a focused investigation/working patch within 2–3 days, followed by a concise summary of the root cause, fix and files changed for your team’s review. Best Regards, Shailender
₹6,500 INR in 2 days
2.0
2.0

Can you provide the dedicated branch and sanitized production logs so I can begin tracing the failure? The main issue is likely a production specific mismatch between the OTP verification state, JWT middleware, or Twilio response handling, since the same flow succeeds in staging and fails after the code is accepted. I would trace the React to Express to Twilio flow, identify the production failure, patch the JavaScript or TypeScript code, and test valid, invalid, and expired OTP cases. I would also review rate limiting and token security while keeping unrelated authentication logic unchanged. I can start immediately and expect the investigation and working patch within 1 to 2 days. I can also provide a clear summary of the fix and all files changed for your team. Best regards, Akif U.
₹6,000 INR in 3 days
1.1
1.1

Hello I am experienced full stack developer. I can help diagnose and fix the production OTP/2FA issue in your eKYC platform. I’ll trace the complete flow from React → Node/Express → Twilio OTP → PostgreSQL → final JWT, reproduce the issue, identify the production-specific cause, and implement a safe fix without affecting the existing login flow. I’ll also review OTP security, rate limiting, JWT handling, and error handling, and provide a brief summary of the fix and files changed. I’m available to start immediately and expect the investigation and fix to take around 2–4 hours, depending on the root cause.
₹1,500 INR in 2 days
1.1
1.1

When it comes to fixing complex issues with eKYC authentication like the one you're currently facing, you need an experienced developer who can hit the ground running. With my solid background of over 10 years in mobile applications, I am well-versed with the technology stack - React, Node/Express API, JWT, Twilio, and PostgreSQL - involved in your project. My strong point in Java assures your code receives meticulous attention to detail. Security is paramount in systems such as yours; I will be on the lookout for potential vulnerabilities. I offer suggestions for security hardening measures and will implement rate-limiting tweaks if deemed necessary. Finally, I understand time is crucial for you. I will dive into the project immediately upon hire and signify the expected duration depending on what more closely examine my
₹7,000 INR in 7 days
0.0
0.0

Hi, Absolutely, I can do that. I will track the OTP request via the React form down to Express/Twilio/JWT, and reproduce the issue present in production only. Next, I will fix the verification process without interfering with the authentication process, and test all possible scenarios – valid, invalid, and expired OTPs as well as the resulting JWT redirect. Also, I will notify about any rate limit/security concerns that I might encounter. As it is specifically a debug session, I will be able to begin immediately after receiving the repository branch. Let me know about the repository.
₹12,500 INR in 7 days
0.0
0.0

Hi, I can help diagnose and fix the production-only eKYC 2FA issue. I’ll trace the complete flow from the React OTP form through the Node/Express API, Twilio verification, and JWT generation to identify exactly where the authentication is failing. I can reproduce the issue, patch the relevant JavaScript/TypeScript code without affecting the existing login flow, and also review the OTP handling for rate limiting and security improvements. I’m available to start immediately and can provide a clear summary of the root cause, fix, and files changed for your team to review and deploy. Please share the Git branch and relevant logs, and I’ll get started.
₹7,000 INR in 7 days
0.0
0.0

Varanasi, India
Member since Sep 3, 2026
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₹600-3000 INR
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₹12500-37500 INR
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₹1000-15000 INR
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