# Fractional CTO Onboarding: What the First 90 Days Should Look Like > Best practices for onboarding a fractional CTO in the first 90 days — what to cover, how to structure access, and how to measure whether it is working. - **Published:** 2025-02-14 - **Author:** Clixo - **Reading time:** 5 min read - **Tags:** fractional-cto, onboarding, engineering-leadership, best-practices - **Canonical URL:** https://clixo.sh/blog/fractional-cto-first-90-days-onboarding-plan The first 90 days of a fractional CTO engagement determine whether the relationship delivers value or quietly drifts. Most failures in fractional CTO arrangements are not caused by the wrong person — they are caused by a poorly structured start. The engagement begins without a diagnostic, responsibilities are undefined, and within six weeks, the fractional CTO is in meetings without clear ownership and the founder is unsure what they are paying for. Here is how to structure the first 90 days so the engagement produces measurable results. ```mermaid gantt dateFormat X axisFormat Day %s section Phase 1 Access and Assessment :a1, 0, 14 section Phase 2 Priority Alignment and Quick Wins :a2, 14, 30 section Phase 3 Process and Architecture :a3, 30, 60 section Phase 4 Execution and 90-day Review :a4, 60, 90 ``` ## The First Two Weeks: Access and Assessment Before a fractional CTO can add value, they need access and context. The first two weeks should be treated as a structured diagnostic period, not an execution sprint. **Access to provide on day one:** - Codebase access (read-only is fine initially) - Production infrastructure observability — dashboards, logs, alert history - Incident history and post-mortems - Product roadmap and current sprint state - Architecture diagrams, if any exist - Access to the engineering communication channels (Slack, Linear, Jira, or whatever you use) **What the fractional CTO should produce in weeks one and two:** - 1:1 conversations with every engineer on the team, structured to understand each person's current work, blockers, and perspective on what is working and what is not - A written first impressions document: what is in better shape than expected, what is concerning, and the three most urgent problems as they see them This document is not a finished assessment — it is a forcing function for alignment. It gives the founding team a chance to correct misunderstandings and gives the fractional CTO a documented baseline to work from. ## Days 15 to 30: Priority Alignment and Quick Wins By the end of week two, the fractional CTO should have enough context to identify where to focus first. Day 15 should be a structured priority alignment session with the founding team and any relevant stakeholders. The output of this session is a written list of the top three to five priorities for the engagement, with a rough time allocation for each. This list needs explicit sign-off from the founding team. When priorities are not written down and agreed on, every urgent request feels equally important and the fractional CTO's time is pulled in all directions. **Quick wins matter in the first 30 days.** A fractional CTO who moves from access to alignment to a visible, concrete improvement within the first month builds credibility with the engineering team and with the founding team. This might be resolving a long-standing technical debate, improving the deployment process so it takes minutes instead of hours, or documenting a critical system for the first time. The improvement does not need to be large — it needs to be visible. ## Days 30 to 60: Building Process and Architectural Direction With context established and quick wins in hand, the middle phase of the first 90 days should focus on the medium-term work that a fractional CTO is uniquely positioned to do: **Establishing or strengthening engineering process.** This might mean introducing architecture decision records, establishing a code review standard, setting up a recurring engineering meeting structure, or defining how technical trade-offs are communicated to the product team. The goal is to install lightweight process that makes the team more consistent without creating bureaucratic overhead. **Setting architectural direction.** By day 45, the fractional CTO should have a working point of view on the highest-leverage architectural decisions the company faces in the next 12 months. Not a final answer — a documented perspective with clear reasoning that the team can review, challenge, and refine. **Identifying team gaps.** The 1:1s in week one surface the skill distribution and performance picture. By day 45, the fractional CTO should have a recommendation on where the engineering team needs to grow — whether through hiring, mentoring, or role restructuring. ## Days 60 to 90: Execution and Accountability The final phase of the first 90 days should be visible execution on the priorities agreed on in week three. This is also the right time for the first formal check-in with the founding team on engagement health. **The 90-day review should cover:** 1. Progress against the agreed priorities — what was completed, what is in progress, what slipped and why 2. A reassessment of priorities for the next 90 days based on what was learned 3. Team feedback — how is the engineering team experiencing the engagement? 4. Scope review — is the current time allocation still right, or does the scope need to expand or contract? ### Measuring Whether the Engagement Is Working By the end of 90 days, you should be able to answer yes to most of these questions: - Do we have a clearer technical roadmap than we did at the start? - Are engineering decisions being made faster and with less founder involvement? - Is the engineering team better organized and more aligned? - Do I understand the major technical risks in our product and have a plan to address them? - Is the engineering team performing better than it was 90 days ago? If the answer to most of these is no, the problem is either the wrong person or a structural issue with the engagement itself. Both are fixable, but fixing them requires an honest conversation at the 90-day mark rather than hoping the next 90 days will be different. If you are setting up an engineering leadership engagement and want to get the structure right from the start, [talk to Clixo](https://clixo.sh/#contact). --- Clixo · 1141 W Bryn Mawr Ave, Itasca, IL 60143, US · [hello@clixo.sh](mailto:hello@clixo.sh) [Start a build](https://clixo.sh/#contact) · [All services](https://clixo.sh/services) · [Agent guide (llms.txt)](https://clixo.sh/llms.txt)