Sana built her wellness app on Replit. Twelve thousand monthly users by month four. The press went out. Then the Replit instance hit its memory ceiling on a Tuesday lunchtime. The app went down for an hour. Customers complained on Twitter. Her churn that week was real.
Rescue Replit production migration · security testing · UK
Replit production migration for the app that keeps crashing. under real traffic.
Your Replit app keeps crashing under real traffic. The default deploy caps around 20-50 concurrent, a single Reserved VM only reaches roughly 500, and there’s no horizontal scaling. In fourteen days, two senior engineers audit your Replit codebase and ship a Replit-to-AWS migration plan: managed Postgres, horizontal-scale architecture, real dev/prod isolation. £8K audit, migration from £28K.
24hreply, from a senior
200+projects shipped since 2019
Senioronly, on the spine
(Why founders book the migration)
Your Replit codebase shipped fast. Now find out what’s missing before someone else does.
A Replit production migration is a 5-day audit first. Two senior engineers read every line, run the attacks, and hand you a written report with a prioritised fix list. You decide what happens next.
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The founder this page is for12K MAU · memory ceiling · 13 findings, 4 critical
Sana built on Replit. The press call went well. Then it hit the memory ceiling.
The next morning the first enterprise prospect’s security questionnaire arrived. Replit couldn’t answer most of it. The seed lead asked the quiet question: “Has anyone independent looked at this yet?” She didn’t have an answer she could say out loud.
We ran the 5-day audit. We found thirteen things, four critical: a single-instance scale wall, no managed DB, no audit log, no MFA path for the SSO she’d promised. She had the written report on day six. This page is for founders who’d rather know what’s in their Replit codebase before the seed lead does.
Replit production migration · the 5-day window
5 days. Four assessments. One written report.
Same shape every audit. NDA Monday morning. Written report Friday afternoon. Hourly support while it runs. Seven Replit audits done since 2024 on this exact cadence.
Day 1
Security assessment
OWASP Top-10 penetration test against your live Replit app. Auth review across sessions, tokens, RLS and anon-key handling. Dependency audit. Secret scanning. Pass / fail per OWASP row with sample code per failure.
Day 2
Architecture review
Schema review, data-flow diagram, state-management audit. Webhook reliability check. A load and scale model at 10× your current traffic so you know what breaks first, and the index that goes missing.
Day 3
Code quality + tests
Static analysis, dead-code map, test-coverage report. Logging and observability audit. CI/CD pipeline review. Deploy-rollback path tested, not assumed. Suggested ADRs drafted for your next engineer.
Day 4-5
Compliance + report
SOC-2 readiness checklist + UK GDPR data handling. DPA template and sub-processor list. A 30-page written report with severity-ranked findings, sample code, and effort estimates in GBP and engineering days.
The security + compliance pack.
Thirty pages your enterprise prospect was about to ask for.
Every line your CFO, CTO and DPO want in writing. Open any row.
Every category tested against your live Replit app. Pass / fail per row, with a sample attack and remediation per failure.
Critical / High / Medium / Low. An effort estimate per fix, in GBP and engineering days, so you can plan the next move.
Token expiry, refresh, RLS coverage, anon-key handling, MFA path. npm audit plus a Snyk-style review of every package with CVE mapping.
Every credential found in the repo and the Git history. A rotation plan for each, so nothing live stays exposed after handover.
Every control assessed. A gap list, and an 8-12 week path to ready. The enterprise questionnaire becomes two hours, not two months.
A signed DPA template, sub-processor list, data-flow diagram and ROPA. The compliance evidence your first enterprise customer asks for.
A one-page architecture and six suggested ADRs for the next engineer. The audit doubles as a diligence pack for the acquirer’s CTO.
Fourteen days to safe. 6 weeks to enterprise-ready. Twelve weeks to acquirer-ready. You pick the line that matches your next raise.
The finding. The severity.
Patterns across seven independent Replit audits. Replit gets you live fast. The scale-up step needs a different runtime. You can’t blame the tool, but you can fix the gaps before someone else finds them.
- 01
“Replit’s default deploy is one always-on instance.”
Under load the memory pressure freezes it. There’s no horizontal-scale path on Replit. We map the move to auto-scaling AWS infra.
- 02
“Replit DB is a key-value store, not relational.”
No transactions, no joins, no foreign keys. Multi-tenant integrity is impossible to enforce. We migrate to managed Postgres or Atlas.
- 03
“Production data lives in a file inside the instance.”
If it restarts wrong, the file is gone. No point-in-time recovery, no backup. We stand up managed storage with PITR.
- 04
“Who changed what, when, and why? No record.”
The SOC-2 audit turns into a six-month panic. We add an append-only audit log on every mutation from the first write.
- 05
“Full name, email and billing address loaded into React state.”
Visible in browser dev tools to anyone logged in. We move sensitive reads server-side and scope them per tenant.
- 06
“Customer-list queries take 14 seconds at 5K records.”
At 50K they time out. Fine today, an outage in three months. We map the missing indexes before scale forces it.
- 07
“Stripe live key in plain text in a .env file that’s in Git history.”
Git blame says “Replit”. The secret-scan report lists every credential with a rotation plan.
- 08
“Login and signup endpoints accept unlimited requests.”
Brute force becomes possible. We add per-IP and per-account limits with alerting on auth anomalies.
- 09
“No unit tests, no integration tests, no e2e tests.”
Every refactor is a leap of faith. The report scopes a coverage baseline and the first Playwright suite for the critical paths.
- 10
“The first enterprise customer asks for a questionnaire and a DPA.”
You have neither, and the deal stalls. The audit ships the SOC-2 readiness checklist, the DPA template, and the sub-processor list.
Sana’s Replit migration · UK wellness · 2025
What the migration actually moved
We audited the Replit-hosted wellness app at 12K MAU, found 13 issues with four critical, then migrated to AWS over seven weeks. The four findings we fixed first.
1K25K
Documented concurrent capacity
£180K
Enterprise deal closed, ACV
“Same Replit UI. New auto-scaling AWS infra. Managed MongoDB Atlas. The enterprise security pack passed first time.”
001
Off the single-instance memory wall
The Replit instance hit its memory ceiling on a Tuesday lunchtime and went down for an hour. We moved to auto-scaling AWS infra with documented concurrent capacity.
002
Managed MongoDB Atlas, with backups
Production data had no managed database and no backup. We migrated to managed Atlas with point-in-time recovery.
003
Audit log on every mutation
There was no record of who changed what, when, or why. We added an append-only audit log so the SOC-2 audit stopped being a six-month panic.
004
MFA path for the promised SSO
She’d promised SSO with no MFA path behind it. We wired the MFA path so the enterprise security pack passed first time.
005
Zero-downtime cutover
The Replit-to-AWS migration ran over seven weeks with a zero-downtime cutover. Customers never saw the move.
Honest answers, real founders
The questions founders actually ask before booking the Replit production migration.
100%
would refer us
Across seven Replit audits, every codebase had at least three critical findings. The audit told me what was missing, ranked by severity, with effort estimates.
What founders actually ask about the audit
Pain-first, soft-second.
The honest answer: probably not yet, and that’s normal. Across seven Replit audits, every codebase had at least three critical findings: an auth gap, a billing race, a tenant-isolation hole, or a missing audit log. Replit is a brilliant builder, not a security platform. The 5-day Replit production migration audit tells you what’s missing, ranked by severity, with effort estimates.
No. Every founder we audit shipped fast with the tools that worked. We’re not judging your speed. We’re telling you what to fix before someone else finds it. The report is written for you, not against you. We’ve never named-and-shamed a client and we never will.
5 days of senior engineering attention on your codebase. An OWASP-grade penetration test against your live Replit app, an architecture review, a load model at 10× current traffic, a SOC-2 readiness checklist, a UK GDPR and DPA pack, and a code quality and test-coverage report. The output is a 30-page written report with severity-ranked findings, sample code per finding, and effort estimates in GBP and engineering days. You can walk away after the audit. Most founders don’t, but the option is real.
No. The audit runs against a staging copy of your codebase, with a separate environment for penetration testing. Your production stays untouched. Your customers don’t see a thing.
Yes. The report is written so your engineer can fix the findings without us. Every finding has sample code, an effort estimate and a recommended pattern. About a third of clients fix in-house, about a third use us for the critical fixes only, about a third move to a full Replit-to-AWS rebuild. All three paths are fine. You decide on day six.
For most cases, yes. The audit doubles as a diligence pack: architecture diagram, six suggested ADRs, threat model, sub-processor list, SOC-2 readiness checklist, DPA template. Seed leads have read it on Friday and approved on Monday. Enterprise customers have used it to skip 70% of their security questionnaire. Full SOC-2 certification is a separate 8-12 week phase, and we hand you the path.
Yes, before anything else. NDA signed inside 30 minutes via DocuSign, mutual template ready. We only need read-only repo access, never write access. Findings are encrypted at rest, accessible only to the engineers on your project, and destroyed 90 days after handover unless you ask for longer retention.
Replit is the builder. We’re an independent auditor. The report you get from us is the one your acquirer’s CTO trusts, because it isn’t coming from the company that built the tool. Our pen test goes against your live app, the dependencies you imported, the integrations you wired in and the deploy infrastructure you chose. Different angle, different findings.
That’s the best time to book it. Founders who run the Replit production migration audit before the diligence call walk into the meeting with the report in hand. Round timelines shorten. The seed lead asks for the audit and you already have it. That’s the conversation we want you to have.
In context
See it in context.
A look at the kind of replit rescue surface we hand over — real screens, real data, documented and yours from day one.
One paragraph. That’s it.
Tell us the Replit app URL, your seed timeline, and the customer you’d like to close next. Mohit replies inside 24 hours: a clear yes, a clear no, or the one question that decides it.
What happens after the email lands
- < 24h
A personal reply.
Yes, no, or the deciding question. Straight to your inbox.
- < 30m
NDA signed.
Mutual NDA via DocuSign. Read-only repo access, never write.
- Day 5
Report on Friday.
A 30-page written audit, severity-ranked, with effort in GBP.