When do Summer 2027 internships open? We tracked 16,307 postings.

Month by month: when last season's internships appeared.

September is the first big month, but it is not the peak. Postings kept arriving all winter, and February and March 2026 were as busy as September 2025. A quarter of the season was up by October 9 and three quarters by March 16.

By field: quant first, hardware last.

Quant internships open months before everything else: half of them were posted by September 23, 2025. Software, AI and product roles reach the halfway point in late January, and hardware not until February 6. If you only look in the fall, you miss most of the software and hardware season.

Summer 2027 is running ahead of last year.

We also read the list as it stood on September 29, 2025, and compared it with the list on September 29, 2026. In the same five fields, Summer 2027 has 3,186 postings against 2,945 for Summer 2026 a year earlier, and 2,116 of this year's are still open. Quant and hardware moved earliest. Software and AI are level with last year, so most of those roles are still to come.

How we measured, and what this does not show.

The list keeps one data file for every season, and its git history keeps every past version. In early February 2026 the file was rebuilt and older postings were archived out of it, so the full Summer 2026 season is the file as it stood on January 30, 2026 plus every Summer 2026 posting added to the current file since, matched by id and web address so nothing is counted twice. Each posting is dated by its date_posted field and counted in the month it falls in (UTC).

The script is public in the Litos website repository (scripts/internship-timeline.mjs), pinned to the exact versions of the file it reads, so anyone can re-run it and check us.

• A date here is the day a posting was added to the list, not always the day the employer opened it. The two are usually close, but a posting can reach the list days late.
• The list is curated and leans toward tech, engineering, quant and product roles at larger employers. It is not every internship in the country.
• The old file had an "Other" category that the current file does not use, so it is left out of every count. Categories were renamed in the rebuild; each old name is mapped to its current one.
• Postings added in July to September 2026 (473, 2.9%) still carry the Summer 2026 term; many are late or off-cycle roles.
• A list can also grow by tracking more employers, so part of any rise can be the list and not the market. The same-day comparison uses the same list a year apart for that reason.

What this means for your search.

If this season follows last season, about four in five Summer 2027 internships are not posted yet. Applying in September and then stopping means missing most of the season.

• Quant and trading: apply now. Half of last season's quant roles were posted by late September.
• Software, AI and product: apply to what is open now, then keep checking every week through March. More than half of these roles arrived after New Year.
• Hardware: the latest field. Half of last season's hardware internships were posted after February 6.
• Do not stop in December. 54.8% of last season's postings came after December 31.
• Keep your resume and answers ready, so a posting that appears in February takes minutes to apply to, not an evening.

Where Litos fits.

Litos keeps your profile, a resume tailored to each job and your answers in one place, so applying to the posting that appears in March is as quick as the one in September. It fills applications page by page, including Workday, and asks you when a detail needs you.

You choose how the last page is handled. With Hold for my final press on, Litos fills everything and waits for you to press Submit. With automatic sending on and no hold, a clean application can go through without another press. Try the sample application, which sends nothing, before using your own resume.