About CESSI
CESSI is a software development company that turns ideas into working products. CESSI focuses on Custom Software Development and Mobile App Development. CESSI employs 2 - 9 people. Their home base is Buenos Aires, Argentina. These details offer a useful starting point when evaluating CESSI.
Where We Specialize
Industry Expertise
Typical Project Size
CESSI Reviews
Write a ReviewCMS that preserved every byte of SEO equity from the old site while adding every feature we needed
Cameron Aldrich / Head of Digital Operations - Northstar Logistics CorpMay 07, 2026
Project summary: The project had a board-facing delivery date tied to a strategic initiative. We needed a partner who would treat that date as their own, not ours.
The integration layer was the part of the project I was most concerned about going in. Our system landscape is complex, several of the upstream APIs we relied on were poorly documented, and two third-party vendors had a history of unpredictable response times on integration questions. This team managed all of that. They documented what the upstream vendors could not, built resilience into the integration architecture where the upstream behaviour was unreliable, and delivered a solution that works as specified in production. I could not have asked for more.
Deep domain knowledge that reduced the discovery overhead significantly, proactive risk identification before issues became incidents, delivery cadence that our stakeholders found reassuring
Their insistence on a detailed functional specification before development began felt like friction at the time. In retrospect, it was the reason the development phase ran without the ambiguity that has derailed similar projects for us previously
Questions & Answers
Project execution that matched the proposal in every dimension that mattered
Marcus Holloway / SVP of Engineering - Vertex Cloud DynamicsApr 25, 2026
Project summary: Time-to-market for new tariff structures had become a direct competitive disadvantage. Our product configuration layer was the bottleneck and it needed to be modernised as a priority.
The integration layer was the part of the project I was most concerned about going in. Our system landscape is complex, several of the upstream APIs we relied on were poorly documented, and two third-party vendors had a history of unpredictable response times on integration questions. This team managed all of that. They documented what the upstream vendors could not, built resilience into the integration architecture where the upstream behaviour was unreliable, and delivered a solution that works as specified in production. I could not have asked for more.
Collaborative culture that made the team feel like a genuine extension of our organisation, strong asynchronous communication across time zones, zero-drama handling of the inevitable mid-project changes
The engagement was priced at the quality level rather than the budget level. We evaluated the alternatives and concluded that the delta was a reasonable premium for the reduction in delivery risk
Questions & Answers
Architecture review that saved us from a vendor decision we would have regretted for years
Radosław Kowalczyk / Head of Development - Wisła Software Sp zooApr 24, 2026
Project summary: Our engineering capacity was committed to maintaining existing systems and could not absorb a net-new build of this complexity. An external partner with the right skills was the only viable option.
Our stakeholder group included board members, clinical leads, compliance officers, and end users — each with different technical literacy and different success criteria. This team navigated that stakeholder landscape as well as any vendor I have seen. They adjusted their communication register depending on the audience without losing the substance. They managed expectations honestly throughout. And they delivered a system that each group can point to as meeting their requirements. That breadth is genuinely uncommon.
Commercially transparent throughout — no hidden assumptions, no bill shock at the end, change requests that were fair and clearly explained rather than used as a margin-recovery mechanism
The engagement was priced at the quality level rather than the budget level. We evaluated the alternatives and concluded that the delta was a reasonable premium for the reduction in delivery risk
Questions & Answers
Infrastructure-as-code that our SRE team treats as a reference example
Lars Pfeiffer / VP of Technology - NordTech Logistik GmbHApr 21, 2026
Project summary: Our internal product thinking was strong but our execution capability in this specific technology domain was limited. We needed depth, not generalism.
We gave this team an aggressive timeline, a technically complex scope, and a client-side project team that was stretched thin and not always available at the speed the engagement required. They absorbed all of that gracefully. Where they needed input they were precise about what they needed and when. Where they could proceed independently they did. The result was a delivery that landed on time despite the constraints on our side, which I regard as evidence of genuine professional maturity.
Deep domain knowledge that reduced the discovery overhead significantly, proactive risk identification before issues became incidents, delivery cadence that our stakeholders found reassuring
The quality of documentation they produce means our team needed to set aside dedicated review time to do it justice — a minor scheduling point rather than a genuine criticism
Questions & Answers
App store launch with a four-point-eight average rating in the first month
Victoria Haines / Chief Product Officer - Solaris Media GroupFeb 03, 2026
Project summary: The project had a board-facing delivery date tied to a strategic initiative. We needed a partner who would treat that date as their own, not ours.
The technical quality of the final deliverable is the easiest thing to point to. The automated test coverage is thorough, the deployment pipeline is reliable, the documentation is genuinely useful rather than ceremonially produced. But the metric I keep returning to is the number of post-launch conversations we have not had to have. No incident calls at two in the morning. No emergency patches. No retrospective discussions about what went wrong. The absence of those events is the evidence I would show to someone considering this vendor.
Collaborative culture that made the team feel like a genuine extension of our organisation, strong asynchronous communication across time zones, zero-drama handling of the inevitable mid-project changes
Time zone coordination required some deliberate overlap management from both sides in the first couple of sprints, after which we had an efficient async rhythm that worked for the whole project
Questions & Answers
A partnership that began with a single project and earned a place on our preferred vendor list
Rupert Ashford / Director of eCommerce - Hargrove Retail PLCJan 07, 2026
Project summary: As a technology business ourselves we apply the same scrutiny to our vendor selection that our clients apply to us. We needed a delivery partner who could meet a standard we would be comfortable being measured against.
Our stakeholder group included board members, clinical leads, compliance officers, and end users — each with different technical literacy and different success criteria. This team navigated that stakeholder landscape as well as any vendor I have seen. They adjusted their communication register depending on the audience without losing the substance. They managed expectations honestly throughout. And they delivered a system that each group can point to as meeting their requirements. That breadth is genuinely uncommon.
Clear and consistent communication adapted appropriately for both technical and non-technical stakeholders, shared tooling that gave our team real-time visibility, reliable sprint delivery throughout
Time zone coordination required some deliberate overlap management from both sides in the first couple of sprints, after which we had an efficient async rhythm that worked for the whole project
Questions & Answers
A partnership that began with a single project and earned a place on our preferred vendor list
Liselotte Bakker / Head of Platform Engineering - Harbour Digital BVJan 06, 2026
Project summary: Matter management had become a significant overhead for our fee earners. Every hour spent on administration was an hour not spent on billable advisory work — the business case was straightforward.
Six months after go-live our platform is processing three times the transaction volume we specified in the original brief. The architecture choices made during discovery accommodated that growth without remediation work. That is the difference between a team that designs for what you tell them and a team that designs for what you are likely to need. We are in conversation about a Phase 2 engagement and I expect to be using this partnership for several years.
Commercially transparent throughout — no hidden assumptions, no bill shock at the end, change requests that were fair and clearly explained rather than used as a margin-recovery mechanism
Their insistence on a detailed functional specification before development began felt like friction at the time. In retrospect, it was the reason the development phase ran without the ambiguity that has derailed similar projects for us previously