Backend engineer focused on the parts that are expensive to get wrong: billing, payment webhooks, auth and LLM features. Sole engineer of the production platform behind an online school with 300+ active students a month (site, CRM, LMS, payments), and of a CRM + LMS for a study-abroad company used daily by 25 staff across 3 branches.
Public billing core: https://github.com/alt-f6/edtech-billing-core (append-only ledger, race-safe payments, 110 integration tests on real Postgres; a randomized test caught a double-refund bug in my own code before it shipped).
Backend engineer focused on the parts that are expensive to get wrong: billing, payment webhooks, auth and LLM features. Sole engineer of the production platform behind an online school with 300+ active students a month (site, CRM, LMS, payments), and of a CRM + LMS for a study-abroad company used daily by 25 staff across 3 branches.
Public billing core: https://github.com/alt-f6/edtech-billing-core (append-only ledger, race-safe payments, 104 integration tests on real Postgres; a randomized test caught a double-refund bug in my own code before it shipped).
Looking for a long-term remote contract with a US or EU team.
Remote: Yes, remote only
Willing to relocate: No
Technologies: TypeScript, Node.js, Python, FastAPI, PostgreSQL, Next.js, React, Docker, Linux, Rust (open-source tooling), OpenAI-compatible LLM APIs
Résumé/CV: https://iusifli.dev/resume
Email: ismail.yusifli86@gmail.com
GitHub: https://github.com/alt-f6
Backend engineer focused on the parts that are expensive to get wrong: billing, payment webhooks, auth and LLM features. Sole engineer of the production platform behind an online school with 300+ active students a month (site, CRM, LMS, payments), and of a CRM + LMS for a study-abroad company used daily by 25 staff across 3 branches.
Public billing core: https://github.com/alt-f6/edtech-billing-core (append-only ledger, race-safe payments, 110 integration tests on real Postgres; a randomized test caught a double-refund bug in my own code before it shipped).
New: pg-interleave, an open-source Postgres proxy for writing deterministic race-condition tests: https://github.com/alt-f6/pg-interleave
Looking for a long-term remote contract with a US or EU team. Available immediately, can overlap with US Eastern hours.
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