About
I'm a backend engineer and co-founder based in Holbrook, MA. I prioritize system design in project building: clear reasons for my database choice, multi-tier caching for speed, with a clear justification for every layer, and multi-tenant authorization that secures user data while making it easy for them to access. Domain-Driven Design isn't a pattern I reach for because it reads well on a resume. I find it the best way to map out complex projects.
I'm currently co-founding Tourgate, a platform that brings every real estate agent's messages and meetings under one roof — with an AI agent that handles the inbox for them. I inherited the starter code, hardened the security, and now own all technical decisions. That kind of end-to-end ownership is exactly what I work toward.
I believe engineers go further with a strong community around them. That conviction started on the cross country team at UMass Boston, where the hardest workouts were only survivable because of the people running alongside me, and it's been reinforced by over eight years of volunteering at church — where I've watched what sustained, consistent presence does over time. It shows up in how I lead technical projects: I meet people individually, make space for every perspective, and move fast once real alignment is there.
Outside of code, I run, mentor younger kids at my church, and am a proud graduate of the Hack.Diversity fellowship.
Experience
2025 — Present
- Inherited starter code from a non-technical co-founder, refactored the entire codebase, hardened security, and now own all technical decisions for the platform.
- Built a unified inbox that aggregates messages from Facebook, Apartments.com, Craigslist, Redfin, MLS, and YGL — plus a Google Calendar integration that surfaces all meetings in one view.
- Implemented an AI agent that autonomously reads and replies to messages with dynamic model routing: simpler messages use a cheaper model, complex ones escalate to a more capable one — cutting API costs without sacrificing response quality.
- Designed a Redis sliding window cache (last 20 messages per user) as the hot layer for the AI context window, with full conversation history persisted in Supabase PostgreSQL.
- Chose PostgreSQL over MongoDB because message threads are relational, queries are field-selective, and row-level security maps directly to per-agent data isolation.
Jan 2025 — May 2025
- Solved 18+ algorithm problems applying dynamic programming, recursion, and hash map strategies with explicit time/space complexity analysis.
- Practiced production Git workflows across the full cycle: branching, pull requests, code review, and Agile sprint collaboration.
Sep 2022 — Present
- Operate in a high-throughput, safety-critical environment processing hundreds of packages per shift; recognized for reliability and consistency under sustained time pressure.
Projects
Pokémon Damage Calculator
1,384ms → 196ms · 7× faster
Filled a gap no tool addressed: Pokémon Radical Red is a ROM hack with custom types, moves, and abilities not covered by any public API — extracted and structured the full dataset from the game's source code, then built the only damage calculator that exists for it. A full-stack app exposing 32 REST endpoints across 1,200+ Pokémon, 900+ moves, and 300+ abilities — with a multi-tier caching strategy where every layer has a distinct justification. Redis handles shared state across serverless instances (cutting enemy-team load from 1,384ms to 196ms — 7×). localStorage caches 6 immutable datasets to avoid network round-trips entirely. User teams and damage calculations are deliberately left uncached: teams are constantly mutating with no size cap; calculations have ~1,000 variable combinations per fight and would yield near-zero cache hit rate.
Tourgate
AI model routing by complexity · Redis sliding window
Co-founded and serve as technical lead. Tourgate pools together real estate agent messages from six platforms (Facebook, Apartments.com, Craigslist, Redfin, MLS, YGL) into a single AI-managed inbox. The AI agent autonomously reads and replies, with dynamic model routing — simpler requests use a cheaper model, complex ones use a more expensive one — reducing API cost without hindering quality. Conversation context is kept fast via a Redis sliding window cache (last 20 messages); full history lives in Supabase PostgreSQL, chosen over MongoDB because message threads are relational and queries never require the whole object.
Car Website — Appointment Booking
Compute-over-store · O(1) Set lookup · write-time race guard
Booking platform for a car detailing business, replacing phone-call scheduling with self-serve appointments. The slot API generates all 19 time windows (8AM–5PM, 30-min intervals) on the fly and subtracts booked ones — only real bookings hit the database. Availability checks run in O(1) by utilizing a Set. A 60-minute same-day buffer filters past slots. Slots are Cloudflare edge-cached for 5 minutes; race conditions are caught at write time with a user-facing fallback.
Student Scheduling System
Scrum Master · ICS conflict detection · Google OAuth
Led a 5-developer Agile team as Scrum Master through a 2–3 month cycle. Managed to get the team to cooperate with one another by meeting each member 1-on-1, taking notes, and combining their ideas into a shared plan. Built the ICS parser that reads university .ical files, extracts unavailable time blocks per weekday, and persists them so the scheduler can reject any conflicting shift assignment.
Pinterest Clone
Hack.Diversity Capstone · Agile collaboration
Hack.Diversity capstone project. Improved performance and debugged an already existing UX of a React/Node.js/Express/MongoDB application in an Agile team environment through targeted pull requests and peer code reviews.
Skills
Languages
Backend
Databases & Caching
Cloud & DevOps
Auth & Security
Architecture
Contact
I'm actively looking for backend and full-stack engineering roles. If you have an opportunity, a question, or just want to talk systems — my inbox is open.
Say helloDesigned & built by Samuel Darius