Proven Experience in Demanding Fields

These are projects where I had a big impact on the technical processes. I have a track record of delivering robust systems for complex business needs, from high-volume marketplaces to secure fintech platforms.

Top Rated by Upwork

Ranked in the top tier of freelance talent based on Upwork client reviews. Proven reliability on large, complex, and high-budget enterprise contracts.

Lukas Liesis — Vetted Top 3% Global Talent

Rigorous screening by Toptal.com passed by only the top 3% of developers worldwide. Guaranteeing elite technical problem-solving.

100% Job Success by Upwork

Flawless execution history verified by Upwork client reviews. Hands-on execution: 4000+ hours, 23 projects.

Commodities Marketplace

Core developer from idea through production, then lead for integrations and infrastructure as the commodities marketplace scaled.

Node.js AWS Idea To Production MongoDB Classical Servers Kubernetes Micro-Services

From idea to $1.5B/yr

I built the initial version of the entire backend.

50+ Microservices

Complex backend powering integrations, legal workflows, and international shipping.

Modern Fintech

Core work on final pricing and financial guarantees across the marketplace.

Direct to CTO

Built all backend and DevOps foundations, later onboarded a couple of dev leads.

Reinvited for scaling

Came back to help during scaling. Migration to Kubernetes and integration with Maersk.

Hostinger website — homepage with Services mega-menu, pricing and domain search

Software Engineering at Hostinger

At Hostinger, I was the 5th developer and contributed to the company's growth to 15M+ users. I developed full-stack customer facing and internal dashboards, integrations, financial automations, staff-managers. Left when company had ±600 global staff. I did this during my master's in physics.

Full-stack development Systems Architecture API Integration Technical Writing and Documentation Stakeholder Management DevOps CI/CD Email Deliverability GitHub SQL Finances automation

15M

Users world-wide

1 Room to 3 HQs

From 1 room of couple people to 3 global HQs growth

First Sales — email deliverability hero: smart infrastructure for cold outreach

CTO for Cold Email Outreach Platform

As the CTO, I built and managed a development team, collaborated with UI designers, and worked directly with the CEO to launch a cold email outreach marketing platform. I built all foundational tech from DevOps, backend, and UI, then onboarded other developers and mentored.

Next.js React Node.js Email Deliverability Artificial Intelligence (AI) REST API DevOps

Founding engineer

I built directly with CEO from idea to production and beyond

0 to 40K MRR

Rapid launch and customer onboarding within 3 months

AI prospecting

Leads automation and AI-powered personalised outreach

Toptal homepage highlighting hire the top 3% of the world's talent

Top 3% Software Engineering at Toptal

As a Software Engineer at Toptal, I was part of the top 3% of developers worldwide. I worked on high-level projects, showcasing deep expertise in software engineering. I delivered a full AI-driven platform build—from technical design through launch—including a distinctive AI agent–based UX for users.

DevOps AWS Node.js CI/CD Artificial Intelligence (AI) Stakeholder Management React Technical Writing and Documentation Systems Architecture Data Architecture

EncargoGo homepage — shop from the U.S. with landed cost pricing and SkyPostal delivery

Interim CTO for EncargoGo

As the Interim CTO, I developed strategies, developed all foundation code and devops. Onboarded developers, and led integrations with shipment partners for EncargoGo, an AI-driven international sales platform.

API Integration Artificial Intelligence (AI) Team Leadership Node.js TypeScript React Next.js Stakeholder Management

Proschooler — homeschool platform UI builder preview

Legacy infrastructure upgrade and full saas rebuild

Worked directly with founder. This is a tool for homeschoolers. I solo built all of it. Devops, API, UIs. All done in 370h.

TypescriptBusiness DevelopmentTDDReactJSNodeJSNextJsMongoDBDynamoDBSQL

Ed-tech

Platform for homeschoolers

Modern Builder

Canva-like UI builder to build pages and later export as PDFs

Principal Software Engineering at Upwork

Recognized as 'Top Talent' on Upwork, leading projects with expertise in AI, TypeScript, JavaScript, Node.js, ReactJs, MongoDB, CSS. Contributed to various high-impact projects on the platform.

CSS JavaScript MongoDB Node.js Artificial Intelligence (AI) TypeScript

100% Job Success

The percentage of jobs that resulted in a great client experience.

4070 Hours

Total hours delivered

Total projects worked on

SaaS Marketplace

I was Co-Founder and CTO

We were a bootstrapped startup valued at $20M at its peak. I built the core platform, hired engineering team, and led product development. We launched dozens of early-stage startups, and I helped them navigate scaling challenges, technical debt, user communication and more. This video has snippets of what Pitchground was. It showcased our global team meeting in Bali.

TypescriptBusiness DevelopmentTDDReactJSNodeJSNextJsMongoDBDynamoDBSQL

Screenshot of the SaaS application for grid subcontractors

SaaS for National Electrical Grid Subcontractors

I solo built this end-to-end. Had to communicate with sub-contractors to learn all how grid subcontractors work, provide insights and technical solutions for business cases. This is not a public app, it's used internally by sub-contractors of national electrical grid operator in Lithuania.

This B2B platform manages the complex lifecycle of national grid infrastructure repairs, upgrades, and maintenance.

Key features included integration with governmental systems, document and inventory management, and communication tools for in-field workers.

Node.jsClassical ServersIdea To ProductionMongoDBReactJs