Software Engineer
Backend systems, developer tooling, and the occasional thing
that has no business being written in C++.

Two years' professional experience developing production SaaS applications, and a knack for making the tool whenever there is no tool. TypeScript & Node, Java & Spring, Python, some Go. Much of what I like to do ends up being around the data: consistency guarantees, auth boundaries, query latencies.

Everything below is my own work and public. For employment history, see LinkedIn.

MaqsudMallick/tendon · Java 17 Spring Boot PostgreSQL Prometheus

The moment you divide your monolith, PostgreSQL will lose control of the constraints it previously maintained automatically. orders.customer_id could refer to a customer that no longer exists, and nothing will complain, since a foreign key cannot cross two databases.

orders.customer_id ──?──► customers.id    100 → 100 ✓   101 → 101 ✓   999 → ??? ✗ orphan

Tendon reconnects them. Aim it at your service databases using read-only credentials, declare the cross-service relationships in a YAML contract, and it constantly hunts for orphan references, reporting violations via REST and Prometheus. No changes needed on your services.

The fascinating problem is that of false positives: the child row may well be validly referring to a parent which has not yet been replicated. Thus, all candidates are aged and re-verified before anything alerts, and the integrity SLOs allow one to tolerate short in-flight references and still find lasting breakage. Pre-alpha.

MaqsudMallick/deepresearch-agent · Python LangGraph Qdrant SQLite

An agent that does research on its own into a problem for an extended period of time. 62 tools in 6 namespaces (web, document, knowledge, synthesis, context, subagent) using a LangGraph state machine with checkpointing to survive interruption and context compression to survive its own length.

Forks out subagents in isolation to allow multiple research threads to run in parallel. Each tool comes equipped with Pydantic-typed inputs and outputs, which is what lets them chain without glue code. Includes the unsexy stuff, too — observability, retry with backoff, rate limiting, and typed errors.

Nextcloud — 5 merged PRs across the Mail app, Android client and Android library:

• mail#13458 — fixed an infinite recursion in the translation feature
• android#17294 — scaled grid thumbnails to fill the available tile width
• android#17251 — use clean internal links when the server reports mod_rewrite working
• android-library#2079 — added the missing talk-password field in shares
• android-library#2057 — added the core mod-rewrite-working capability

AI-Powered Medical Waste Management with IoT — IEEE, March 2025. An IoT and deep learning pipeline for real-time medical waste classification using ResNeXt, at 97.93% accuracy.

TypeScript JavaScript Java Python Go C++ SQL · React Next.js Tailwind Redux TanStack · Node.js NestJS Express Spring Boot TypeORM Mongoose LangGraph · PostgreSQL MySQL MongoDB Redis Qdrant · Docker GitHub Actions AWS Linux Prometheus Jest Zod OpenAPI

Jadavpur University — BE Computer Science, 2020–2024. CGPA 8.98.

_{maqsudmallick@gmail.com · LinkedIn}