Senior TypeScript/PostgreSQL Developer — Independent Payment Platform Reviewer

Elevation is developing Elevation Bonds, an existing platform for bond subscriptions, payments and investor administration. We are preparing new client campaigns managed by Elevation while continuing platform development. We are looking for an experienced freelance developer to provide independent technical reviews. We build the platform ourselves using AI-assisted development. Your role is to assess the reliability of critical changes and identify risks or missing evidence that should prevent release. We are interested in a long-term, on-demand collaboration following a successful initial engagement. INITIAL ASSIGNMENT: PAID 4–6-HOUR TRIAL REVIEW We will agree on one bounded change and a fixed code version before the review starts. You will examine the relevant code, any database migrations, tests and release/recovery plan, and reproduce selected checks in an isolated environment using synthetic data. You will deliver a concise report covering: • Specific findings, severity and supporting evidence. • Checks performed and their limitations. • Missing evidence and actionable recommendations. • An independent recommendation on the agreed next step. This is not a complete platform audit within six hours. Additional review work and reassessment of subsequent changes will be agreed separately. RELEVANT EXPERIENCE • Strong TypeScript/Node.js and PostgreSQL experience; Next.js and Prisma are relevant. • Practical experience with payments, webhooks, transactions, concurrency and idempotency. • Safe database migrations, releases, backup/restore and recovery from partial failures. • Security and isolation between client data and payment accounts. • Clear communication and willingness to recommend against release when evidence is insufficient. • Mollie Connect/OAuth, secure token handling, SEPA, Railway and GitHub Actions are a plus. The trial is review-only: no implementation, deployments or production access. After selection, access will be limited, temporary and read-only, with MFA and confidentiality arrangements. Using our code or data in external AI/cloud tools requires prior permission. TO APPLY Please share your profile, hourly rate, earliest availability and availability for future on-demand reviews. Briefly answer: 1. Describe a payment or webhook issue involving duplicate processing, concurrency or an uncertain outcome. What was your role, and how was the solution verified? 2. How would you scope a 4–6-hour review, and what would you deliver? 3. When would you recommend against release despite passing tests? Remote collaboration is welcome. Professional English is sufficient; relevant review documentation will be provided in English.