How to build a portfolio: structure, case studies and format
A portfolio sits next to your resume and shows, through two or three case studies, how you approach a problem and what your work changed.
How it differs from a resume
A resume summarizes your whole background in short lines: employers, roles, education and skills. A portfolio picks a few projects and shows them in depth, with the problem, your process, the output and the result. Designers are almost always asked for one, and it is common for product managers, marketers, developers and data analysts as well. Even when a posting only mentions it as optional, a short portfolio gives the reviewer evidence the resume cannot hold.
Structure: cover, intro, cases, contact
Start with a cover that states your name, the role you are applying for and the year. Follow with a short introduction: one or two sentences on what you do and the kind of problems you like to solve. The core is two or three case studies, ordered with the most relevant first rather than the most recent. Close with a contact slide that repeats your email and any demo, code or web portfolio links.
Writing a case study
Tell each case as problem, process and outcome. Open with the problem and a number that shows its size, then describe the few actions you took and the decisions behind them. State the period, your role, the team size and your contribution so the reader can separate your work from the team's. End with results in numbers and one line on what you learned or would do next.
Images and visuals
Use images that explain a decision: sketches, flows, charts, screens or before-and-after comparisons. Give every image a one-line caption, because the portfolio is often read without you there to explain it. Only use your own work, or material you have permission to show, and credit photographers, agencies and collaborators. Remove client names, customer data and internal figures that are confidential, or replace them with ratios and generic labels.
Length and submission format
Aim for about 4 to 8 slides per case study, and keep the whole deck short enough to read in a few minutes. Submit it as a PDF so the layout stays the same on any device, and keep the file under the limit the posting sets, often around 10 to 20 MB. Export images at screen resolution rather than print quality to keep the size down. Use a clear file name such as 'Name_Role_Portfolio.pdf', and make every link in the file clickable.
Checks before sending
Open the PDF on a laptop and a phone to confirm the text is readable and the images are sharp. Click every demo, code and web link from a private browser window to be sure it is public and working. Compare project names, dates and titles with your resume so they match exactly. Finally, read it once as a stranger would, and fix any slide that only makes sense to someone who was on the project.