Selleo

Selleo is a custom software development company founded in 2005 and headquartered in Poland, with a team of 100+ developers, designers, and product specialists. The company works with founders and CTOs across EdTech, HRTech, SaaS, and enterprise segments, focusing on predictable delivery, direct engineer access, and code ownership. They position themselves as a partner for teams shipping under pressure: clear milestones, weekly demos, early risk flags, and no vendor lock-in.

Services and capabilities

Selleo's core offering splits across three models. Full-cycle product development covers discovery, scoping, design, development, testing, and launch—Selleo handles the entire arc. Dedicated team augmentation brings experienced developers, designers, and product specialists into existing workflows. Rapid prototyping validates ideas quickly before committing to full builds.

On the technical side, the company specializes in custom software, SaaS platforms, mobile apps (React Native), AI integration, DevOps, and QA. Their technology stack includes React, Node (with NestJS), Ruby on Rails, React Native, and Ember. They also offer an in-house LMS available in three flavors: open-source (self-hosted), SaaS (hosted), or custom-built.

UX/UI design work includes UX research via interviews and surveys, wireframing, interactive prototyping, high-fidelity design, usability testing, and WCAG accessibility compliance. For AI specifically, Selleo implements model deployment, vector databases, MLOps pipelines, monitoring, and cost optimization. They also integrate features like AI-powered personalization, augmented reality, and voice/visual search into custom builds.

Industry focus runs deep in EdTech (learning management systems, virtual classrooms, gamification), HRTech (applicant tracking, payroll, talent management, performance management), FinTech, e-commerce, real estate, and healthcare.

Notable work

Named case studies in the source include a Middle East collaboration platform (MVP release with two Product Owners, closely collaborative), LMS builds across education and corporate learning, a gaming-inspired LMS, modern HRM tools, AI-powered government helpdesk digitization, and scaled e-commerce experiences. The source mentions these span SaaS, React, Ruby on Rails, and mobile work, though detailed project outcomes are not quantified in the scraped material.

How they work

Engagement begins with a call to a technical team lead and business analyst, establishing scope and cost. If alignment holds, Selleo assembles a team matched to project requirements and kicks off with clear goals, role assignments, communication channels, and timelines. Work runs in agile sprints with steady cadence, demo-based check-ins, and direct developer access. Within 2–4 weeks, clients receive a delivery plan, clickable prototype (if needed for alignment), and a scoped MVP backlog. Selleo emphasizes predictable rituals, short feedback loops, pragmatic QA, and handover-ready code. A 2-week trial sprint is available with no contracts or commitments.

Team and credentials

Selleo has 100+ people across developers, designers, and tech leads. Clutch rates them 4.7/5 overall (4.6 quality, 4.5 schedule, 4.5 cost, 4.7 willing to refer). Clients stay for an average of 4.5 years. The company holds certifications in software testing and cloud architecture, is Scrum-certified, and was awarded Forbes Diamonds 2025 for consistent growth and business excellence. Team members speak English and work from a single location. Specific client testimonials praise their Ruby on Rails expertise, technical skills in emerging tech, proactive communication, and market impact contributions.