Open to opportunities

Tom Callaghan

@tomcallaghan

Message

Data-driven engineer specializing in backend systems, Web3 protocols, and scalable API architecture.

Ireland

Message

What I'm looking for

I seek engineering roles building scalable backend systems or Web3 protocols, with emphasis on automation, API architecture, and cross-functional impact.

I am a data-driven engineer with 8+ years bridging software development and financial analytics, focused on building scalable APIs, automation, and distributed systems. I combine Python-based automation with strong backend engineering to turn raw data into strategic enterprise assets.

I've led engineering efforts across Web3 DeFi protocols and enterprise deal management — deploying high-throughput smart-contract systems, architecting API migrations to modular V3 designs, and automating account lifecycle and analytics workflows to reduce manual overhead.

My background spans fintech, enterprise SaaS, and blockchain startups where I improved system stability, increased mobile transactions, and delivered financial reporting/forecasting automation that informed pricing and deal strategies.

Experience

Work history, roles, and key accomplishments

Senior Software Developer

tiiny.host

Aug 2025 - Jan 2026 (5 months)

Drove engineering best practices, led code reviews and PR management, and migrated legacy API endpoints to a scalable NestJS V3 architecture to improve modularity and developer velocity.

NestJS TypeScript MongoDB AWS API Design Code Review CI CD

Full Stack Developer

Upwork

Jan 2022 - Aug 2025 (3 years 7 months)

Built backend services with NestJS for a token launchpad, developed a sports betting API and proxy for Polymarket, and integrated a CMS with a Next.js frontend for a Web3 jobs platform.

NestJS Python Next.js React Django Web3

Deal Management Analyst

VMware

Oct 2020 - Oct 2024 (4 years)

Managed global deal structuring and pricing for enterprise software, coordinated with sales, finance, compliance and legal teams to negotiate and execute enterprise ELAs, and automated Tableau dashboards to improve reporting efficiency.

Deal Structuring Pricing Strategy Financial Analysis Tableau Stakeholder Management Contract Negotiation ELA

Lead Developer

LiquidCrypto

May 2022 - Dec 2023 (1 year 7 months)

Deployed LP token staking contracts and a Swap supporting 2M+ liquidity pools, built a Bridge integrating LQDX and five bridges, and improved server stability by 30% through a distributed API redesign.

Smart Contracts Solidity Next.js React API Design Cross Chain Bridges Performance Optimization

Data Analyst

PepsiCo

Jan 2020 - Mar 2020 (2 months)

Led a data cleanse for supply chain using Python and Pandas, created visualizations and reports with Matplotlib and Jupyter to track data inconsistencies in the cola processing plant.

Python Pandas Jupyter Matplotlib Data Cleaning ETL Automation Supply Chain Analytics

Financial Analyst

Datastacks

Jul 2019 - Nov 2019 (4 months)

Reported key financial metrics including ACV and ARR, automated a Salesforce deal health scoring algorithm with Python reducing manual tracking by 30%, and performed UAT and sandbox analysis for CRM enhancements.

Financial Analysis Python Salesforce Automation UAT Reporting

Sales Planning Analyst

InverEnergy Ireland

May 2018 - Jun 2019 (1 year 1 month)

Managed customer relationships and sales forecasting for wholesale clients, performed monthly volume nominations and tracking for inland, marine and clean fuels, and led contract renewals and pricing for core business sectors.

Sales Forecasting Customer Relationship Management Renewals Pricing Volume Nominations Reporting Forecasting