Engineering Partners, at Your Side

Senior engineering teams that integrate with your culture and roadmap. We own delivery, maintain predictability, and apply AI where it adds value.

Dedicated teams that fit your tech stack and organization

Compact, senior teams that integrate with your culture and workflows, from MVP to growth-stage.

Dedicated squads with senior lead

Permanent lead/architect for the duration of the engagements.

Typical team: Lead/Architect, 2–4 engineers, optional QA
Rapid onboarding & development

We align on scope and milestones quickly, then ship in short cycles for fast feedback.

Leveraging AI where it adds value, always with senior engineering oversight
Trusted & secure

NDAs and clear IP ownership by default. We follow Secure by Design principles. Security considerations inform how we architect, build, and deliver.

Least privilegePeer reviews

Long-Term Partners, Proven Results

We build dedicated teams that embed into your company, take proactive responsibility, and deliver measurable outcomes you can count on.

Fintech
iPartners logo
Sydney
Since 2017 we have been the engineering partner behind iPartners growth from startup to a leading investment platform in Australia and Asia. We built the platform from the ground up and continue to own architecture delivery and reliability.
13 core peak 31 engineers
Since 2017
AUD 4.5B plus AUM
10,000 plus active investors
SixSides have delivered their expertise for over seven years to help us build a market leading SaaS product. With exceptional work ethic and deep technical knowledge they continue to meet project goals and integrate seamlessly with our teams.
Photo of Norman King - CTO iPartnersNorman King - CTO iPartners
Consumer, AI
Tertulia logo
NYC
Since 2021, we have built and scaled Tertulia’s AI-driven bookstore from concept to launch. We delivered backend, mobile, data, and e-commerce, enabling personalized recommendations for millions of books and community-driven discovery.
5 engineers
Since 2021
Tens of millions of books indexed
Hundreds of millions of tweets processed
I began my career at Bell Labs working with many world-class software engineers, and at Artsy we had a great NYC-based engineering team, many of whom have now started companies themselves or work for top companies like Amazon, Meta, Microsoft, etc. I know what good engineering looks like. Martin and Daniel, the two SixSides partners who’ve led our engineering team for the last four years, are excellent, technically as well as culturally. On a practical level they speak great English, are essentially on eastern time zone, and the prices are very competitive.
Photo of Sebastian Cwilich - CEO, TertuliaSebastian Cwilich - CEO, Tertulia
SaaS, Creator Tools
Tertulia for Authors logo
NYC
Since 2024, we have built and scaled Tertulia’s site builder for authors. Writers create professional websites from an ISBN or Instagram profile, with backend, frontend, domains, payments, and analytics delivered end to end.
5 engineers
Since 2024
Thousands of author sites launched
Custom domains and SSL automated
More recently, the SixSides team built an entirely new author website building platform (essentially “Squarespace for authors”), from ideation to launch with paying customers in less than 6 months. Now, five months after launch, we’ve scaled to thousands of paying subscribers while simultaneously adding functionality with weekly new releases — all while maintaining and improving the performance of the platform. I don’t think any engineering team I’ve worked with in the past, including top NYC-based engineers costing much more, would have been able to deliver at this level of speed and quality.
Photo of Sebastian Cwilich - CEO, Tertulia for AuthorsSebastian Cwilich - CEO, Tertulia for Authors

Leveraging AI for Improved Productivity

AI tools are used throughout the development lifecycle, always overseen by senior engineers. Our R&D team continuously tests and incorporates new tools that add value without introducing excessive risk.

Architecture & Design

AI helps compare design options, surface trade-offs, and draft outlines. Engineers validate inputs and make final decisions to keep systems scalable and maintainable.

Build & Development

AI accelerates scaffolding and pattern implementation and assists with PR reviews by spotting inconsistencies and suggesting improvements. Developers remain accountable for correctness and long-term quality.

Testing & QA

AI proposes test cases, highlights coverage gaps, and detects flaky results. QA and engineers validate critical paths to combine automation with human judgment.

Release & Operate

AI drafts changelogs, deployment notes, and incident summaries to reduce manual work. Engineers ensure secure releases, monitor signals, and maintain predictable, audit-ready operations.